1. Field of the Invention
This invention relates to a disk recording and reproducing apparatus in which recording monitoring (simultaneous recording and monitoring) can be performed with a single pickup system, and more particularly to a disk recording and reproducing apparatus suitably applied to a master recording apparatus for producing a cutting master disk which is an original disk to be used to manufacture a large number of compact disks (CDs) or mini disks (MDs) in a musical disk manufacturing factory.
2. Description of the Related Art
When it is tried to manufacture a large number of compact disks or mini disks in a musical disk manufacturing factory, a recording medium for a cutting master which is an original for such compact disks or mini disks must be prepared. Normally, a magnetic tape is used as the recording medium. FIG. 36 shows an outline of a conventional master recording apparatus which is used to produce an original.
Referring to FIG. 36, the master recording apparatus 10 includes a multi-channel tape recorder 11 by which original musical signals are recorded. Normally, a digital video tape recorder (U-matic video tape recorder) is used as the multi-channel tape recorder 11, and an original sound tape on which musical signals are recorded is produced. Musical signals are recorded in a plurality of, for example, 24, channels on the original sound tape, and the musical signals from the original sound tape are converted into 2-channel signals and recorded onto a master tape by means of a master recorder 12.
The master tape is supplied to an editing apparatus 13, on which editing processing necessary for conversion of data into data of a format conforming to a type of a disk to be cut or some other factor is performed to produce a master tape for final cutting. Using the master tape for cutting, corresponding disks such as compact disks or cassette tapes are manufactured in a disk manufacturing factory.
As musical disks have become increasingly popular in recent years, a demand for disks as original recording media is increasing. When a disk is used as an original, original signals can be recorded linearly without compressing the same and can be edited with a single original without destroying the same.
Also when a disk is used as an original rather than a tape, it is convenient if a simultaneous monitoring function is provided when recording musical signals onto the disk.
In order to allow editing of a disk, the disk preferably is a writable or re-writable disk. In order to realize simultaneous monitoring with recording (hereinafter referred to as recording monitoring) where a writable disk is used, a pickup system for recording data onto a disk and another pickup system for monitoring the disk must be provided. However, where the pickup systems are constituted in a multi-beam system in this manner, the construction of the pickup systems and a signal processing system are complicated.